CFX 5 & TASCFLOW comparison

We are simulating a secondary flow (gas turbine leakage flow) using CFX5.6 and TASCflow. For the same BC, and same CFD model, we see a significant difference between CFX5 and TASCflow results (pressure drop). Does anybody has clue / suggestions for this issue. We have seen good comparison for statoric components. But for rotating components, this difference is seen at UD as well as higher order schemes.